This invention relates generally to balloon tip catheters and more particularly to a catheter in which the balloon is specially constructed for use in the destruction of venous valve.
Veins have long been used by vascular surgeons to serve as vascular conduits to bypass blocked or clogged arteries. For example, the saphenous vein is commonly used to bypass various arteries that are plagued by blockage, including clogged leg arteries and coronary arteries. When the saphenous vein is used in leg surgery, in situ procedures are generally preferred because they allow the vein to remain in place without having to be removed and implanted at a new location. As can easily be appreciated, this minimizes damage to the tissue and increases the chances that the vein will function successfully to bypass the clogged part of the artery.
However, using the saphenous vein for in situ bypass procedures is not always possible. One major problem is that the veins are equipped with one way check valves that allow blood to flow in only one direction through the vein. If the flow direction in the artery that is to be bypassed is opposite the direction of flow allowed in the vein, it is necessary to remove the vein and turn it end for end before it can be attached to the artery as a bypass conduit. Thus, the vein cannot remain in place and the advantages of the in situ procedure are lost.
The presence of the venous valves also creates problems in other types of operations. For example, when the saphenous vein is used in coronary bypass surgery or other bypass surgery, it can only be oriented in one way because of the valves, and this prevents the vein from being reversed in situations where reversal of its orientation is otherwise desirable.
It is the principal goal of the present invention to provide a catheter which can be used to destroy venous valves without damaging the lining or wall of the vein so that the vein can be used in bypass surgery without regard to directional limitations. Although the invention is especially well-suited for in situ surgical procedures, it is desirable in many other types of surgery for the venous valves to be removed, and the invention thus finds use in a wide variety of surgical applications.
In accordance with the invention, a balloon tip catheter is equipped with a specially shaped balloon having an arrowhead shape. The base of the arrowhead presents an annular groove extending around the catheter tube so that the balloon can be moved past the valve in a deflated position, inflated to the arrowhead shape, and then pulled back so that the lip or edge of the valve is received in the groove of the balloon. Further pulling of the catheter causes the balloon to tear the valve away from the wall of the vein so that the vein can thereafter be used in an in situ procedure or removed and implanted elsewhere without regard to its orientation.
Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description.